Segment Information - Financial Information Related to Company's Reportable Segments (Detail) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net sales	$ 5,576	$ 5,464
Segment EBITA	623	583
Corporate expenses	(118)	(136)
Amortization of intangible assets	(96)	(97)
Restructuring and impairment costs	(111)	0
Equity Securities, FV-NI, Unrealized Gain (Loss) Restricted	10	(21)
Net financing charges	(52)	(85)
Income from continuing operations before income taxes	256	244
Building Solutions North America
Segment Reporting Information [Line Items]
Net sales	2,167	2,116
Building Solutions EMEA/LA
Segment Reporting Information [Line Items]
Net sales	928	907
Building Solutions Asia Pacific
Segment Reporting Information [Line Items]
Net sales	629	613
Global Products
Segment Reporting Information [Line Items]
Net sales	1,852	1,828
Building Technologies & Solutions \| Building Solutions North America
Segment Reporting Information [Line Items]
Net sales	2,167	2,116
Segment EBITA	258	250
Building Technologies & Solutions \| Building Solutions EMEA/LA
Segment Reporting Information [Line Items]
Net sales	928	907
Segment EBITA	90	77
Building Technologies & Solutions \| Building Solutions Asia Pacific
Segment Reporting Information [Line Items]
Net sales	629	613
Segment EBITA	72	66
Building Technologies & Solutions \| Global Products
Segment Reporting Information [Line Items]
Net sales	1,852	1,828
Segment EBITA	$ 203	$ 190

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